IBM PC hacking

[Fred Cisin]

On Tue, 13 Sep 2005, jim stephens wrote:
> It was called "Superboard" and was no relation to Supermicro, which
> came much later.  It had a bios that usually worked, but also had,
> conveniently, a spot for up to 6 eprom chips, so you could put in a
> PC bios if you could get a copy.

The "Superboard"s that I got were bare boards, with NO parts.
I filled them with Augat sockets.  By the time that I was done,
my soldering had improved substantially.

> The PC used either EProms, (16K I think) and the Roms that were
> shipped with the BIOS were registered.  The standard Data I/O would
> not read them since they were not programmable, and needed their
> output enabled to read the data.

I just went into DEBUG, copied the 5150 ROMs to an available segment,
and wrote them to files.  For reasons that I never found out, The
IBM ROMs, and copies thereof, could not handle DRIVPARM (present in
DOS 3.20 and above.  But most aftermarket ROMs could.

> First systems had a 63 watt P/S, and IBM cards if you could find
> them for video.  Also there was no floppy controller on the first
> board.

But there were also bare boards available for FDC, CGA, etc.

> Maybe others of you can recall expansion card makers, of such
> things as serial, parallel, memory, floppy, then hard drive, etc.

The first aftermarket memory board was from Boulder Creek Systems.
It even did ECC!

I have some Tecmar "modular multifunction" boards to sell off the next
time that I can make it to VCF.  Unfortunately, I am stuck with teaching
Saturdays this semester :-(

--
Grumpy Ol' Fred     		cisin at xenosoft.com